Fungi play important ecological roles and affect society through their activities as decayers, mutualists, and pathogens of plants and animals. Their enzymes are critical to biofuel production. Despite their importance, there is little known about how many fungi obtain food. Mycorrhizal fungi obtain sugars from plants in exchange for helping their host plants take up nutrients, and saprotrophic fungi obtain their energy and nutrients from decomposition of dead organic matter. Whether fungi switch between nutritional strategies is a key question in the evolutionary ecology of fungi. Recently, measuring carbon-12, carbon-13, and carbon-14 isotopes has been shown to reliably assess nutritional strategy, and therefore provides new opportunities to examine the evolution of nutritional strategies in fungi. This study will use archived fungi from Australia, Asia, and the US to conduct a broad survey of fungal nutritional strategies. A site-specific study at the Harvard Forest research site in Massachusetts will also be used to examine whether fungi can switch nutritional strategies. These studies will greatly expand knowledge on the links among fungal function, phylogeny, and ecology. The broader scientific impacts of the proposed research will result from integrating functional (isotopic) methods and genetic methods in a novel collaboration that should stimulate interest within the larger community of evolutionary biologists, ecologists, and mycologists. These methods could be readily expanded to Europe and Africa to include the global distribution of mushroom-producing fungi. This project will also incorporate current scientific research into specific educational activities designed to inspire future scientists including high school (fungal forays), college (Clark University's ACE Summer Institute, Research Experience for Undergraduates at Harvard Forest, the UNH Undergraduate Research Conference), and graduate students.
